1. Field of the Invention
The present invention relates to a connector.
2. Description of the Related Art
A blow-by gas collection piping system mounted on a vehicle has a plurality of tubes that connect an engine and an air intake duct to each other. Blow-by gas that has leaked from the space between the cylinder of the engine and the piston is fed it back to the air intake duct and reutilized. Thus, the blow-by gas is prevented from being discharged to the atmosphere.
Maintenance of the blow-by gas collection piping system may require removal of a connection portion between tubes. A visual check then is performed to determine whether the connection portion has been reconnected to the tubes.
However, the engine can be operated, even though the connection portion is removed from the tubes. In this case, the blow-by gas is discharged to the atmosphere if the engine is driven without noticing that tubes are disconnected from each other.
The present invention has been made in view of the above-described situation. Accordingly, an object of the present invention is to provide a connector that allows an operator to detect whether a connection portion has been removed from a tube.
To achieve the object, in the present invention, there is provided a connector having a pair of first housings and a second housing that can be fit on one of the first housings. Two metal fittings are provided on the first housings or the second housing. The metal fittings are placed in an unconductive state when the housings are not placed in a fit-on position. However, the metal fittings are placed in a conductive state when the housings are placed in the fit-on position. The first housing has a short-circuit terminal displaceable between a conductive position at which the housings are placed in the conductive state and an unconductive position at which the housings are placed in the unconductive state. An urging member is provided for urging the short-circuit terminal to the unconductive position from the conductive position, when the housings are not placed in the fit-on position.
Preferably, the second housing can be fit on the first housing is provided on an outer wall of a device, such as an engine or the like. The second-side is the side from which it is difficult to move the device, as compared with the first-side.
Preferably, each of the housings is provided at an end of a fluid-passable tube; the first housing has a cylindrical portion connectable to the second housing and a continuity inspection portion provided adjacent the cylindrical portion and accommodating the detection terminals and the short-circuit terminal. The continuity inspection portion has a slide for sliding the short-circuit terminal between the conductive position and the unconductive position. The second housing has a pressing portion that presses the slide to the conductive position in an operation of fitting the first housing and the second housing on each other. The slide slides in the same direction as a direction in which the cylindrical portion fits on the second housing or separates from the second housing. The term xe2x80x9cfluidxe2x80x9d means gas, liquid, powder, granular material flowing inside a tube. The pressing portion may be provided in the vicinity of the tube.
Preferably, a waterproof member is provided at a mounting portion where the slide is mounted on the first housing and is provided at a mounting portion where electric wires connected to the detection terminals are mounted on the first housing to make the mounting portions watertight. The waterproof member may be provided in the slide member or the first housing. The waterproof member may be provided in the detection terminal or the first housing.
According to the invention, two of the detection terminals are provided on the first housing. The detection terminals become electrically conductive to each other through the short-circuited terminal when the housings are placed at the fit-on position. Accordingly, it is possible to check whether the housings have been normally fitted on each other, by detecting whether the detection terminals are electrically conductive to each other.
The construction for checking whether the tubes are in a normal connection state is provided collectively on the first housing, and it is unnecessary to provide the second housing with an electrical construction or a waterproof construction. Therefore, in the case where the blow-by gas collection piping system is used to collect the blow-by gas from an engine, it is possible to cope with a spatial restriction by mounting the other-side housing on an outer wall of the engine.
When the second housing has been fitted in the cylindrical portion of the first housing, the slide of the continuity inspection portion is placed at the conductive position, because the slide is pressed by the pressing force applied thereto by the pressing portion. On the other hand, when the second housing has been removed from the cylindrical portion, the slide of the continuity inspection portion is placed at the unconductive position because the slide is not pressed by the pressing force applied thereto by the pressing portion. Therefore, it is possible to detect whether the housings have been fitted properly on each other. Further, it is unnecessary to provide the second housing with an electrical connection construction. Thus, the entire construction of the blow-by gas collection piping system can be simplified by providing the second housing on the outer wall of the device.
Let it be supposed that the detection terminals are accidentally conductive to each other owing to penetration of water. Because the mounting portions are provided with the waterproof members, respectively, it is possible to prevent an operator from interpreting the state in which the housings are disconnected from each other for the state in which they are placed at the fit-on position. Further, it is unnecessary to provide the second housing with an electrical construction or a waterproof construction for continuity inspection. It is only necessary to provide the first housing with the continuity inspection portion. Thus, it is possible to simplify the construction of the second housing.